During the operation of a medical ultrasound instrument, the efficiency of the high voltage transmitters can be optimized by setting the supply voltage of the transmitters to the minimum level required for the transmitters to operate. This supply optimization reduces the power consumed by the instrument and reduces the heat generated by the power supply and transmitters.
The optimum power supply voltage for the transmitters will depend upon the particular mode (i.e. B-mode, doppler, color flow, or continuous wave) in which the ultrasound machine is operating. The operating mode may change very rapidly, and optimum supply voltage can change at millisecond rates as the operating modes are intermixed.
In situations where the operating mode is changing rapidly, previous power supplies have not been able to change output voltage rapidly enough to track the mode changes without introducing lengthy delays at each mode change. In order to eliminate these delays when intermixing modes, the supply must be set to provide adequate voltage for the worst case mode. The other modes in the operating sequence then operate at higher than optimal voltage levels, reducing electrical efficiency and creating excess heat.
It would be desirable then to have a means for optimizing the power supply voltage to the high voltage transmitters for each operating mode, even when the modes are rapidly intermixed.